Well my main OS hard drive, and all three optical drives are located on the motherboard IDE. The promise controller just handles two additional hard drives I have. I am using all the updated firmware/software for the promise controller.

I think the promise controller is a very good lead but just seems silly that Plextor would break that compatibility (presumably between 2.08 and 2.09).

I will try disabling the Promise controller and see what happens.

Thanks.